Decreasing electrical resistivity of gold along the melting boundary up to 5 GPa

ABSTRACT

The electrical resistivity of gold was experimentally measured at high pressures from 2 to 5 GPa and temperatures ∼300 K above melting. The resistivity decreased as a function of pressure and increased as a function of temperature as expected. The temperature dependence of resistivity in the solid and liquid phases are comparable to 1 atm results. The observed melting temperatures at each pressure agree well with previous experimental and theoretical studies. The essential result of this study is that resistivity decreases along the pressure-dependent melting boundary, conflicting with a prediction of invariant behavior as reported in the literature. This result is discussed in terms of the interaction between s and d-bands as both pressure and temperature increase along the melting boundary. The thermal conductivity of gold was calculated from the measured electrical resistivity using the Wiedemann-Franz law. The temperature-induced effect on the thermal conductivity at high temperatures is as expected in both the solid and liquid phase while the pressure-effect shows some variability.

KEYWORDS:

• Gold
• electrical resistivity
• melting boundary
• thermal conductivity
• high pressure-temperature

Acknowledgements

We are grateful for the help of Jonathan Jacobs, who guided the high precision machining of the pressure cell components. We thank the reviewer for comments which helped improve the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Richard A. Secco http://orcid.org/0000-0001-5029-659X

Wenjun Yong http://orcid.org/0000-0002-2114-6100

Additional information

Funding

This work was supported by funds to R.A.S. from the Natural Sciences and Engineering Research Council of Canada [grant number 105604-2013] and the Canada Foundation for Innovation [project number 11860].